Photoactivable glycolipid antigens generate stable conjugates with CD1d for invariant Natural Killer T cell activation

Research output: Contribution to journalArticle

Authors

  • Shalu Sharma Kharkwal
  • Amareeta K Besra
  • Simon J North
  • Stuart M Haslam
  • Anne Dell
  • Judith Hobrath
  • Padraic Quaid
  • Himanshu Kharkwal
  • Maurice Zauderer
  • Del Besra
  • Steven A Porcelli

Colleges, School and Institutes

Abstract

Activation of invariant natural killer T lymphocytes (iNKT cells) by α-galactosylceramide (α-GC) elicits a range of pro-inflammatory or anti-inflammatory immune responses. We report the synthesis and characterization of a series of α-GC analogues with acyl chains of varying length and a terminal benzophenone. These bound efficiently to the glycolipid antigen presenting protein CD1d, and upon photoactivation formed stable CD1d-glycolipid covalent conjugates. Conjugates of benzophenone α-GCs with soluble or cell-bound CD1d proteins retained potent iNKT cell activating properties, with biologic effects that were modulated by acyl chain length and the resulting affinities of conjugates for iNKT cell antigen receptors. Analysis by mass spectrometry identified a unique covalent attachment site for the glycolipid ligands in the hydrophobic ligand binding pocket of CD1d. The creation of covalent conjugates of CD1d with α-GC provides a new tool for probing the biology of glycolipid antigen presentation, as well as opportunities for developing effective immunotherapeutics.

Details

Original languageEnglish
JournalBioconjugate Chemistry
Early online date7 Aug 2018
Publication statusE-pub ahead of print - 7 Aug 2018